Indonesian President Joko Widodo has asked his ministers to make "serious" efforts to strengthen the country's foreign exchange reserves amid pressures caused by a global trade war.

"The country needs dollars now," Widodo said in a cabinet meeting on Tuesday. "I don't want to keep doing meetings without good implementations."

Indonesia requires foreign inflow to finance its current account deficit and the central bank has spent around $12 billion of its forex reserve in recent months to defend the rupiah, which has lost around 6 percent this year.